function add(a,b,k){var result=a+b;return k(result)}function sub(a,b,k){var result=a-b;return k(result)}function mul(a,b,k){var result=a*b;return k(result)}function div(a,b,k){var result=a/b;return k(result)}function arithmetic(){
  add(4,4,function(a){
    sub(a,2,function(b){mul(b,3,function(c){div(c,2,function(d){console.log(d)})})})})};
